In the dosimetry calculations, a correction was made for the difference in attenuation between Co and I using a measured linear broad-beam attenuation factor of 0.145 cm−1 57Co and 0.138 cm−1 for I. Blood samples were obtained at 10 min, 1 h and subsequently directly before each whole-body scan.
The intercept value (0.001 cm−1) was 1% of the value for water (0.1 cm−1) and was therefore ignored when calculating the calibration factor for converting the linear attenuation coefficient into a quantitative measure of density.
Gamma-ray shielding competence of silicate and borate heavy metal oxide glasses has been investigated using linear attenuation coefficients, effective atomic numbers and exposure buildup factors (EBF).
A calibration experiment was first conducted on a bone sample to determine the conversion factor from 31P signal intensity to linear attenuation coefficient μ.
Water cement ratio, cement quantity, volume ratio of lead-slag aggregate and silica fume quantity were selected as control factors and slump, compressive strength and gamma linear attenuation coefficient were considered as the quality responses.
These discrete anelastic attenuation factors varying with frequency were fitted with the linear function shown in Fig. 5. Therefore, the frequency-dependent Q model generalized for the whole of Taiwan, as the input parameter of simulation using the random vibration theory, can be expressed as: Fig. 5. Shear-wave Q model (represented as the solid line) adopted in this study.
Also, a new parameter (composition factor k) given by the ratio of the linear attenuation coefficients from the two tomograms is introduced.
linear attenuation coefficient, mass attenuation coefficient, penetration depth, equivalent atomic number, exposure buildup factor have been computed for seven different concretes (ordinary, hematite serpentine, ilmenite limonite, basalt magnetite, ilmenite, steel-scrap and steel magnetite) in the energy region of 0.015 15.0 MeV.
Due to the dependence of Hounsfield units (HU) on various factors including patient shape and size [10], we also compute and collect linear attenuation coefficients (LAC) [11] and investigate their correlation with ACC.
T lung = linear attenuation coefficient of lung (cm−1).
